In a city where the law has been rendered non-existent, Yuki and his best friend Tetsu break into the offices of the Seidoukai to steal, in a desperate attempt to finance his ailing brother's hospital bills. They ultimately fail but instead spark the interest of the mob's young leader, Kazutaka Hyodo, who offers Yuki a deal he can't refuse: pay him a visit at his office once a week and all hospital bills will be taken care of. Yuki accepts without hesitation and in order to keep his end of the deal, starts paying Hyodo the visits he asked for…

Note: From volume 6 onward chapter numbering diverges from the magazine version.